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User's Guide
The QNX OS User's Guide is intended for all users of a QNX OS system, from system administrators to end users.
Getting to Know the OS
Welcome to the QNX OS!
QNX OS compared with Unix
If you're familiar with Unix-style operating systems, you'll feel right at home with QNX OS—many people even pronounce QNX to rhyme with Unix (some spell it out: Q-N-X).

QNX Momentics IDE User's Guide
QNX Software Development Platform
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
- OS Components
  - Boot Optimization Guide
    The Boot Optimization Guide describes techniques you can use to reduce the time from your board's initial power on until you have a fully functional QNX system running on the board.
  - Building Embedded Systems
    The Building Embedded Systems guide is intended for developers who are developing or building BSPs for QNX OS embedded systems.
  - Customizing a BSP
    While QNX provides Board Support Packages (BSPs) for many common platforms and their individual variants, in some cases, you need a BSP for a board that QNX does not provide. If this is the case, you can modify a QNX BSP or develop your own.
  - High Availability Framework Developer's Guide
  - High-Performance Networking Stack (io-sock) User's Guide
    This guide contains instructions for implementing and using the QNX OS High-Performance Networking Stack and its manager, io-sock.
  - PCI Server User's Guide
  - QNX Helpers Developer's Guide
    These libraries provide QNX helpers, including helpers that assist with logging, string conversion, and number and type sizes.
  - SMMUMAN User's Guide
  - SPI Framework Technote
  - System Analysis Toolkit (SAT) User's Guide
  - Technotes
  - User's Guide
    The QNX OS User's Guide is intended for all users of a QNX OS system, from system administrators to end users.
    - Getting to Know the OS
      Welcome to the QNX OS!
      - QNX OS compared with Unix
        If you're familiar with Unix-style operating systems, you'll feel right at home with QNX OS—many people even pronounce QNX to rhyme with Unix (some spell it out: Q-N-X).
      - QNX OS compared with Microsoft Windows
        QNX OS and Windows have different architectures, but the main difference between them from a user's perspective is how you invoke programs.
      - How QNX OS is unique
        The QNX OS consists of a microkernel (procnto) and various processes. Each process—even a device driver—runs in its own virtual memory space.
    - Logging In, Logging Out, and Shutting Down
      QNX OS is a multiuser operating system; it lets multiple users log in and use the system simultaneously, and it protects them from each other through a system of resource ownership and permissions.
    - Managing User Accounts
      This chapter explains how user accounts work, how users can change their password by using the passwd utility, and how system administrators can use the passwd utility and edit account database files to create and maintain users' accounts.
    - Using the Command Line
      Like QNX 4, Unix, and DOS, the QNX OS is based on a command-line interface that you might want or need to use instead of the GUI.
    - Working with Files
      In a QNX OS system, almost everything is a file; devices, data, and even services are all typically represented as files. This lets you work with local and remote resources easily from the command line, or through any program that works with files.
    - Using Editors
      An editor is a utility designed to view and modify files.
    - Configuring Your Environment
      The Building Embedded Systems guide describes what happens when you boot your system, and what you can do to customize it. This chapter describes how you can customize the environment that you get when you log in, and then describes some of the setup you might need to do.
    - Writing Shell Scripts
      Shell scripting, at its most basic, is taking a series of commands you might type at a command line and putting them into a file, so you can reproduce them again at a later date, or run them repeatedly without having to type them over again.
    - Working with Filesystems
      The QNX OS provides a variety of filesystems, so that you can easily access DOS, Linux, as well as native Power-Safe disks.
    - TCP/IP Networking
      The term TCP/IP implies two distinct protocols: TCP and IP. Since these protocols have been used so commonly together, TCP/IP has become a standard terminology in today's Internet. Essentially, TCP/IP refers to network communications where the TCP transport is used to deliver data across IP networks.
    - Backing Up Data
      No matter how reliable your hardware and electrical supply are, or how sure you are that you'll never accidentally erase all your work, it's just common sense to keep backups of your files. Backup strategies differ in ease of use, speed, robustness, and cost.
    - Securing Your System
      Now that more and more computers and other devices are hooked up to insecure networks, security has become a very important issue. The word security can have many meanings, but in a computer context, it generally means preventing unauthorized people from making your computer do things that you don't want it to do.
    - Fine-Tuning Your System
      This chapter describes how you can improve your system's performance.
    - Understanding System Limits
      Resources on a system tend to be finite (alas!), and some are more limited than others. This chapter describes some of the limits on a QNX OS system.
    - Examples
      This appendix includes samples of some of the files described in this guide.
    - Glossary
- Graphics
- Programming
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX OS system and developers who want to create a QNX OS resource manager free from vulnerabilities.
- Utilities & Libraries
- Migrating to QNX OS 8.0
QNX Software in the Cloud
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

QNX OS compared with Unix

Updated: March 08, 2024

QNX SDP8.0User's GuideUser

If you're familiar with Unix-style operating systems, you'll feel right at home with QNX OS—many people even pronounce QNX to rhyme with Unix (some spell it out: Q-N-X).

At the heart of the system is the microkernel, procnto, surrounded by other processes and the familiar Korn shell, ksh (see the Using the Command Line chapter). Each process has its own process ID, or pid, and contains one or more threads.

Note: To determine the release version of the kernel on your system, use the uname -a command. For more information, see its entry in the Utilities Reference.

QNX OS is a multiuser OS; it supports any number of users at a time. The users are organized into groups that share similar permissions on files and directories. For more information, see Managing User Accounts.

QNX OS follows various industry standards, including POSIX (shell and utilities) and TCP/IP. This can make porting existing code and scripts to QNX OS easier.

QNX OS's command line looks just like the Unix one; QNX OS supports many familiar utilities (grep, find, ls, gawk) and you can connect them with pipes, redirect the input and output, examine return codes, and so on. Many utilities are the same in Unix and QNX OS, but some have a different name or syntax in QNX OS:


Unix	QNX OS	See also:
adduser	passwd	Managing User Accounts
at	cron
dmesg	slogger2, slog2info
fsck	chkqnx6fs, chkdosfs
ifconfig eth0	ifconfig em0	TCP/IP Networking
man	use	Using the Command Line
pg	less, more	Using the Command Line

For details on each command, see the QNX OS Utilities Reference.